Process for making die-plates.



are 'r WALTER R. BARDSLEY, 0F PHILADELPHIA, PENNSYLVANIA.

PROCESS FOR MAKING DIE-PLATES.

No Drawing.

To all whom it may concern:

Be it known that I, WALTER a citizen of the United Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Processes for Making Die-Plates; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, which form a part of this specification. i

This invention relates to certain new and useful process for making a die or matrix of zinc, copper or other metal, the same to be used for embossing of printing plates so that said printing plates may be used without an overlay or other make-ready.

To this end and to such others as the invention may pertain, the same consists of the steps comprising the process hereinafter described.

1. In carrying out my process, I first polish and clean the sheet of metal until it is entirely free from grease.

2. The metal surface thus cleansed is then coated with sensitized fish glue or albumen solution, such as is commonly used in connection with the photo-engraving processes and is then dried in a subdued light.

8. The impression is then made upon the sensitized metal plate, with any suitable full-bodied greasy ink, of the printing plate it is desired to treat or emboss.

4. After this step of the process, to the surface of the plate is applied a fine opaque powder, such for instance as dragons blood or the like. The excess powder upon the surface is then brushed away by a soft camels hair brush or a piece of fine cotton wool.

5. The plate is then exposed to either a natural or artificial light for a length of time sufficient to make the sensitized solution on the plate insoluble in water.

6. The plate is then washed with turpentine, benzole, benzin or other suitable solvent for the purpose of removing the ink and powder from the plate, care being taken not to scratch the surface.

7. The surface then is treated by the use of a soft roller with a thin coating of good quality etching or lithograph transfer ink,

R. BARDSLEY,

Specification of Letters Patent.

States, residing at Patented @et. 19, 1915.

Application filed January 27, 1915. Serial No. 4,765.

care being taken to insure an even spreadmg of the coating over the entire surface of the plate.

8. The plate is then immersed in a tray of clear water and rubbed gently with a piece of cotton wool until the portions that have not been exposed tothe light are washed clean. The portions of the plate covered by the ink mentioned. in the third stage of the operation will be found to be unaffected by the light and consequently will be soluble 1n water.

9. The plate is then powdered with dragons blood or other suitable etching powder and is heated slowly until the powder melts and the back of the plate is then coated with a suitable acid resist, such as shellac or asphaltum.

10. The plate is then placed in a tray containing acid, suitable for the metal used, and is etched from 1/1000 to 2/1000 of an inch to any depth desired. After the etching, the surface of the plate is cleansed by the use of a proper solvent, such as benzole, turpentine or caustic potash, which latter may be used when the coating is particularly hard to remove. Then, after drying, the portions of the plate which are of satisfactory depth are painted with an acid resist, such as asphaltum and the plate is then etched to another degree. This painting and etching is alternately repeated until the necessary number of steps is acquired, usuallv three or four.

During the carrying out of my process from the second to the seventh step of the operation, care should be taken that no moisture other than that specified comes in contact with the plate. During the second, third, fourth, sixth and seventh steps of the operation, the plate must be keptin a subdued light. It is necessary that the back of the plate should be constantly protected by a coating of shellac or asphaltum against the action of acid. The metal sheets used in the process must necessarily be of even thickness throughout, ordinarily from 10/1000 to 18/1000 of an inch having been found satisfactory.

In the carrying out of the process, the third and fourth steps of the process may be modified as, for instance, an impression may be taken, from the printing plate it is desired to emboss, upon a sheet of suitable paper, using an abundance of ink. A transf l" from this proof on paper can be made When this alternative operation is used, the

tall'ic surface,

operation and may be placed in :a photographic frame, after which it may betreated to the steps described in the fifth operation.

sixth operation will be unnecessary.

Having thus described my invention, what I claim to be new and desire to secure by Letters Patent is A method of making a metallic die for use in embossing, consisting in cleansing a mecoating the same with an albumen solution and drying the same in a subdued light and upon which an impression Copies of this patent may be obtained for five cents each, by

with a suitable fine. opaque powder,

is made by the use of ink, after which to the surface of the plate is applied a fine afterward exposing the plate to light a suilicient length of time to cause the sensitized solution to the plate to be insoluble in water, afterward washing the plate with a solvent to remove the ink and powder from the plate, then treating the surface of the plate with a coating of lithograph transfer ink, immersing the plate in liquid, washing off the portions which have n t been exposed to the light. afterward applying suitable etching powder to the surface :and heating until the powder melts. and afterward etching the plate.

In testimony whereof I hereunto afiix my signature in presence of two witnesses.

WALTER R. BARDSLEY.

Witnesses:

Josern 8 Loan, R. REMICK.

addressing the Commissioner of Patents Washington, D. C. 

